DraperQFTAdder
class DraperQFTAdder(num_state_qubits, kind='fixed', name='DraperQFTAdder')
Bases: qiskit.circuit.library.arithmetic.adders.adder.Adder
A circuit that uses QFT to perform in-place addition on two qubit registers.
For registers with qubits, the QFT adder can perform addition modulo (with kind="fixed") or ordinary addition by adding a carry qubits (with kind="half").
As an example, a non-fixed_point QFT adder circuit that performs addition on two 2-qubit sized registers is as follows:
a_0: ─────────■──────■────────────────────────■────────────────
│ │ │
a_1: ─────────┼──────┼────────■──────■────────┼────────────────
┌──────┐ │P(π) │ │ │ │ ┌───────┐
b_0: ┤0 ├─■──────┼────────┼──────┼────────┼───────┤0 ├
│ │ │P(π/2) │P(π) │ │ │ │
b_1: ┤1 qft ├────────■────────■──────┼────────┼───────┤1 iqft ├
│ │ │P(π/2) │P(π/4) │ │
cout_0: ┤2 ├────────────────────────■────────■───────┤2 ├
└──────┘ └───────┘References:
[1] T. G. Draper, Addition on a Quantum Computer, 2000. arXiv:quant-ph/0008033
[2] Ruiz-Perez et al., Quantum arithmetic with the Quantum Fourier Transform, 2017. arXiv:1411.5949
[3] Vedral et al., Quantum Networks for Elementary Arithmetic Operations, 1995. arXiv:quant-ph/9511018
Parameters
- num_state_qubits (
int) – The number of qubits in either input register for state or . The two input registers must have the same number of qubits. - kind (
str) – The kind of adder, can be'half'for a half adder or'fixed'for a fixed-sized adder. A half adder contains a carry-out to represent the most-significant bit, but the fixed-sized adder doesn’t and hence performs addition modulo2 ** num_state_qubits. - name (
str) – The name of the circuit object.
Raises
ValueError – If num_state_qubits is lower than 1.
Attributes
ancillas
Returns a list of ancilla bits in the order that the registers were added.
calibrations
Return calibration dictionary.
The custom pulse definition of a given gate is of the form
{‘gate_name’: {(qubits, params): schedule}}
clbits
Returns a list of classical bits in the order that the registers were added.
data
Return the circuit data (instructions and context).
Returns
a list-like object containing the tuples for the circuit’s data.
Each tuple is in the format (instruction, qargs, cargs), where instruction is an Instruction (or subclass) object, qargs is a list of Qubit objects, and cargs is a list of Clbit objects.
Return type
QuantumCircuitData
extension_lib
Default value: 'include "qelib1.inc";'
global_phase
Return the global phase of the circuit in radians.
header
Default value: 'OPENQASM 2.0;'
instances
Default value: 16
metadata
The user provided metadata associated with the circuit
The metadata for the circuit is a user provided dict of metadata for the circuit. It will not be used to influence the execution or operation of the circuit, but it is expected to be passed between all transforms of the circuit (ie transpilation) and that providers will associate any circuit metadata with the results it returns from execution of that circuit.
num_ancillas
Return the number of ancilla qubits.
num_clbits
Return number of classical bits.
num_parameters
Convenience function to get the number of parameter objects in the circuit.
num_qubits
Return number of qubits.
num_state_qubits
The number of state qubits, i.e. the number of bits in each input register.
Return type
int
Returns
The number of state qubits.
parameters
Convenience function to get the parameters defined in the parameter table.
prefix
Default value: 'circuit'
qubits
Returns a list of quantum bits in the order that the registers were added.